So now it supports Flash web sites as you can see from the screen shot Google provided:

But if you try it on the Converse site you get whiteness.

Why? Well maybe Converse needs to follow some of Google's guidelines to get these to work:

Make sure that your site has a reasonable, seamless experience for visitors without Flash. This may involve creating HTML-only equivalents for your Flash-based content that will automatically be shown to visitors who can't view Flash. Providing a good experience for this case will improve your preview and make your visitors happier.

If Flash components are rendering but appear as loading screens instead of actual content, try reducing the loading time for the component. This makes it more likely we'll render it properly.

If you have Flash videos on your site, consider submitting a Video Sitemap which helps us to generate thumbnails for your videos in Instant Previews.

If most of the page is rendering properly but you still see puzzle pieces appearing for some smaller components, these may be fixed in future crawls of your page.